The invention relates to a belt feeder for an automatic gas pressure loaded-weapon, in particular a machine cannon.
Such a belt feeder and its drive is, for example, disclosed in German published unexamined patent application No. 2,809,505 (corresponding to U.S. Pat. No. 4,273,025). With this known belt feeder there may occur a jamming of a cartridge by the feed shaft sprocket wheel after completion of the transporting phase of the belt feeder and thereby its discharge through the breech is hindered. Thereby the cartridge can be damaged during discharge and an increased load is placed on the feed shaft sprocket wheel and, due to this, a lowering of the firing cadence may occur. These drawbacks do particularly strongly manifest themselves when, during firing the end of the belt is reached or is nearly reached, because then there still is exerted the same forces of the drive mechanism on the reduced mass of the ammunition belt.
In our co-pending application Ser. No. 255,843 there is described a recoil brake for a feed shaft sprocket wheel which is required for transporting the ammunition belt. This recoil brake limits at the end of the belt the rotation of the corresponding sprocket wheel shaft by having a locking pawl engage a cam affixed to the shaft in a jerky fashion. The engagement, respectively disengagement of the locking pawl is effected in accordance with the teachings of the previously mentioned patent application by means of a control pin which engages a cam surface of the drive gear which is actually slidably displacable in the housing of the arrangement. In practice it has however been established that the force which is transferred from the spring via the locking pawl to the control pin produces friction between the control pin and the driving gear and during the axial movement friction between the control pin and the housing. As a consequence of this, the frictional forces can influence and produce malfunctioning and thereby lower the firing cadence of the weapon. During the return rotation of the driving gear the control pin moves the locking pawl out of the engagement position. This can make it possible that when a long ammunition belt is used, due to its mass moment of inertia the ammunition belt may trailingly slip which has the effect that the ratchet wheel impacts against the ratchet point of the locking pawl which moves out of its safety position and this can also cause an excessive wear.